This invention relates to a device and a method for testing the ability of pipe joints to withstand high pressures. It also relates to a method for making gaskets useful in the device.
The present invention is particularly adapted to enable tests of pipe joints for relatively large diameter pipes, that is, pipes two feet in diameter and up. The device can be used with somewhat smaller pipes, but it becomes more significant with the larger diameter pipes, because heretofore the testing of these pipes has been quite difficult. The difficulty has been due in part to the fact that the gaskets intended to isolate the pipe joint and to withstand fluid test pressure applied against the pipe joints have often been displaced and even blown out of the device when the desired testing pressure was applied.
It is an object of the present invention to provide a pipe joint tester in which the gaskets that seal against the pipe wall are retained in place even when high testing pressure is applied to the space between the gaskets and the joint. Thus, leakage, if any, will take place at the pipe joint rather than through the testing apparatus.
Among other problems solved by the invention are those of being able to expel air from the space between the gaskets, the joint tester, and the pipe and ensure that substantially all such air has been displaced by liquid, when the test fluid is a liquid. The device is also operative for testing joints against the leakage of pressurized gases.
Another object of the invention is to provide a joint tester in which a self-contained apparatus is easily moved through a pipeline and set in place at the joint.
Another object of the invention is to provide a safe testing system, avoiding the problems inherent when a gasket is inflated by air.
Another object is to provide an improved method for making inflatable gaskets.
Other objects of the invention will appear from the description below.